With respect to catalysts for subjecting propylene to gas-phase catalytic oxidation with molecular oxygen to synthesize acrolein and acrylic acid, there have hitherto been made a large number of proposals, and in general, catalyst systems thereof are frequently dealt as the same system. Among those, a technology regarding an atomic ratio of iron and cobalt and nickel is described in Patent Document 1, and it is described that by allowing the atomic ratio of iron to cobalt and/or nickel to fall within a specified range, the activity and selectivity can be improved. Patent Document 2 discloses a technology of preparing plural catalysts in which while making an atomic ratio of iron to cobalt and/or nickel constant, an atomic ratio of cobalt relative to an atomic ratio of cobalt and nickel is changed, and filling them in two or more layers of reaction bands within a reaction vessel and using it. Patent Document 3 discloses a technology regarding an annular unsupported catalyst in which an atomic ratio of cobalt relative to an atomic ratio of molybdenum and an atomic ratio of cobalt relative to an atomic ratio of iron are set to specified values, respectively. Patent Document 4 discloses a technology regarding an iron raw material and discloses that by using iron molybdate as the raw material, a catalyst in a high yield can be produced. Patent Document 5 discloses a catalyst in which a part of a bismuth raw material is added to a dry powder containing other catalyst constituent elements. Patent Document 6 discloses a catalyst in which bismuth trioxide is used as a bismuth raw material. Patent Document 7 discloses a technology regarding an atomic ratio of bismuth to molybdenum, an atomic ratio of cobalt and/or nickel to molybdenum, an atomic ratio of iron to molybdenum, and an atomic ratio of an alkali metal to molybdenum and discloses a catalyst containing a specified crystal and not containing molybdenum trioxide. Patent Document 8 discloses a catalyst in which the range of a value A obtained by subtracting a value of 1.5 times of an atomic ratio of cobalt and an atomic ratio of iron from an atomic ratio of molybdenum is defined, and furthermore, an atomic ratio of bismuth to A and an atomic ratio of cobalt to iron are restricted; however, an atomic ratio of nickel is not investigated. In the light of the above, in the conventional technical ranges, there are a lot of cases where extensive investigations are made for the purpose of optimizing the atomic ratio of each of the elements to molybdenum; however, any inventions in which an atomic ratio of nickel relative to an atomic ratio of bismuth, an atomic ratio of nickel relative to an atomic ratio of an alkali metal component, and an atomic ratio of bismuth relative to an atomic ratio of an alkali metal component are investigated in detail, thereby clarifying effects thereof (activity, effective yield, and mechanical strength) have not been found yet.